Activity与View的生命周期

Activity七个基本的生命周期方法：onCreate、onStart、onResume、onPause、onStop、onDestory，这六个生命周期方法两两相互对应，外加一个onRestart方法。

自定义View时，常需要复写的方法：onMeasure、onLayout、onDraw以及onSizeChanged、onFinishInflate。

structure=>operation: 构造方法
onAttachToWin=>operation: onAttachToWindow
onMeasure1=>operation: onMeasure
onSizeChanged=>operation: onSizeChanged
onLayout1=>operation: onLayout
onMeasure2=>operation: onMeasure
onLayout2=>operation: onLayout
onDraw=>operation: onDraw
onDetachedFromWindow=>operation: onDetachedFromWindow
structure->onAttachToWin->onMeasure1->onSizeChanged->onLayout1->onMeasure2->onLayout2->onDraw->onDetachedFromWindow

先蛮测下呗，在MainActivity中给七个生命周期方法打log；自定义FrameLayout和TextView的子类，即CustomViewGroup和CustomView，仅仅给五个生命周期方法打log；这两个自定义View直接放到Activity的xml布局中：

生命周期的执行流程

启动Activity

顺序	MainActivity	CustonViewGroup	CustomView
1	onCreate before setContentView
2		CustonViewGroup(ctx, attrs)
3			CustomView(ctx, attrs)
4			onFinishInflate
5		onFinishInflate
6	onCreate after setContentView
7	onStart
8	onResume
9			onMeasure
10		onMeasure
11			onMeasure
12		onMeasure
13			onMeasure
14		onMeasure
15			onMeasure
16		onMeasure
17		onSizeChanged
18			onSizeChanged
19			onLayout
20		onLayout
21			onMeasure
22		onMeasure
23			onMeasure
24		onMeasure
25			onLayout
26		onLayout
27		onDraw
28			onDraw

按下回退键

顺序	MainActivity	CustonViewGroup	CustomView
1	onPause
2	onStop
3	onDestroy

重新进入MainActivity并按下Home键

顺序	MainActivity	CustonViewGroup	CustomView
1	onPause
2	onStop

回到MainActivity

顺序	MainActivity	CustonViewGroup	CustomView
1	onRestart
2	onStart
3	onResume
4		onDraw
5			onDraw

onFinishInflate

顺序	CustonViewGroup	CustomView
1		onFinishInflate
2	onFinishInflate before
3	onFinishInflate after

onMeasure

顺序	CustonViewGroup	CustomView
1	onMeasure before
2		onMeasure
3	onMeasure after

onSizeChanged和onLayout

顺序	CustonViewGroup	CustomView
1	onSizeChanged before
2	onSizeChanged after
3	onLayout before
4		onSizeChanged
5		onLayout
6	onLayout after

onDraw

顺序	CustonViewGroup	CustomView
1	onDraw before
2	onDraw after
3		onDraw